The invention relates to a motor-vehicle seat with a spring core resting on a subframe and surrounded by a top frame, each top frame portion pointed in the longitudinal direction of the vehicle being supported relative to the subframe via a stay preventing floating movements and limiting lateral compression movements.
A motor-vehicle seat of this type, in which the stay is designed respectively as a stabilizing wire, can be taken as known from German Patent Specification 3,442,734. The stablizing wire is formed as an extension of a spring turn and can therefore be produced in a simple way by mechanical means. However, it is not possible for seats without a stay to be retrofitted with the stabilizing wire. Also, the know stay affords sufficient lateral support, but relatively high forces are imparted to the top frame under the associated compression movements.
An object of the invention is to provide a stay which can easily be adapted to meet different requirements and with which even motor-vehicle seats without a stay can also be equipped subsequently, and which exerts no reaction on the top frame under compression movements taking place at the edge.
This object is achieved by means of a motor vehicle seat wherein the stay is designed as a foam block which is fixed to the frame and which is inserted between two springs stretched from the subframe to the top frame and at least partially surrounds these positively.
A simple fixing to the subframe, in interaction with the two stretched springs, is obtained if the foam block is supported on the raised edge of the subframe according to certain preferred embodiments of the invention.
The properties of the foam block which have a stabilizing effect are enhanced according to certain preferred embodiments wherein the foam block initially projects beyond the contour of the top frame, during the tensioning of the seat covering the foam block being compressed and being pressed with prestress against the stretched springs.
An even better lateral hold as a result of less compression is obtained if the top of the foam block serves as a rest for a seat spring aligned essentially in the transverse direction of the vehicle and fastened to the top frame according to certain preferred embodiments of the invention.
In a further development of preferred embodiments of the invention, it is contemplated to equip the underside and/or top of the foam block with webs projecting from this and formed on during the operation of foaming the foam block, the spring characteristic of which is such that the supporting effect of the foam block is fully utilized only at a load above that occuring during normal motoring.
A tilting movement of the webs is counteracted if these webs intersect one another with the effect of forming a wafer pattern according to certain preferred embodiments. The pattern can be regular or also irregular. Furthermore, the web height can differ over the extent of the pattern, so that depressions of differing depth are obtained next to one another.
Simple foaming moulds can be used and an easy mould-removal operation is achieved if the webs have a trapezoidal cross-section giving rise to a progressive spring characteristic and with sides tapering outwards towards one another.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.